Answer:
<em>a)</em> <em>1.392 x 10^6 g/cm^3</em>
<em>b) 8.69 x 10^7 lb/ft^3</em>
<em></em>
Explanation:
mass of the star m = 2.0 x 10^36 kg
radius of the star (assumed to be spherical) r = 7.0 x 10^5 km = 7.0 x 10^8 m
The density of substance ρ = mass/volume
The volume of the star = volume of a sphere = 
==> V = 
= 1.437 x 10^27 m^3
density of the star ρ = (2.0 x 10^36)/(1.437 x 10^27) = 1.392 x 10^9 kg/m^3
in g/cm^3 = (1.392 x 10^9)/1000 = <em>1.392 x 10^6 g/cm^3</em>
in lb/ft^3 = (1.392 x 10^9)/16.018 = <em>8.69 x 10^7 lb/ft^3</em>
A solution has a pOH of 7. 1 at 10∘c. Then the pH of the solution given that kw=2. 93×10−15 at this temperature is 7.4 .
It is given that,
pOH of solution = 7.1
Kw =2.93×10^(-15)
Firstly, we will calculate the value of pKw
The expression which we used to calculate the pKw is,
pKw=-log [Kw]
Now by putting the value of Kw in this expression,
pKw =−log{2.93×10^(-15)}
pKw =15log(2.93)
pKw=14.5
Now we have to calculate the pH of the solution.
As we know that,
pH+pOH=pKw
Now put all the given values in this formula,
pH+7.1=14.5
pH=7.4
Therefore, we find the value of pH of the solution is, 7.4.
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We use the following formula to calculate the number of atoms:
n (mol) = N(number of atoms) / NA
N(He) = n(mol) · NA
N(He) = 2,0 moles · 6.02·1023 = 12.04·1023 atoms
By unit conversion, the aspirin contains 7.72 grains.
We need to know about unit conversion to solve this problem. The unit conversion can be used to convert a unit to another unit. It can be defined as
a = xb
where a is unit a, b is unit b and x is the constant of conversion.
From the question above, we know that
m = 0.5 gram
unit conversion
(1 grain = 64.8 mg)
Convert the unit conversion to 1 mg
1 grain = 64.8 mg
1/64.8 grain = 64.8/64.8 mg
1 mg = 1/64.8 grain
Convert the aspirin mass to grain
m = 0.500 g
m = 0.5 x 10³ mg
m = 0.5 x 10³ x 1/64.8 grain
m = 7.72 grain
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Answer: Sheila's top brick will be cooler than Ralph’s top brick, because Sheila’s started with more total energy, so less energy had to transfer for both her bricks to reach the same total energy.
Explanation:
